Pink painted tank by Czech artist David Cerny is seen on the boat at Vltava river in Prague, Czech Republic, 20 June 2011. The Czech Republic recalls the 20th anniversary of the departure of Soviet forces during the festival 'Week of freedom'. The last Soviet soldiers left Czechoslovakia after 23 years of occupation. EPA/MATEJ DIVIZNA.

PRAGUE (AP).- A pink tank has temporarily returned to the heart of Prague to mark the 20th anniversary of the Soviet troops' withdrawal.

Tank No. 23 was originally put on display on a Prague square in 1945 to commemorate the liberation of Czechoslovakia by the Red Army after the WWII occupation by Nazi troops.

For many, it became a symbol of the 1968 Soviet-led invasion that crushed the liberal reforms of Alexander Dubcek and ended an era known as the Prague Spring.

David Cerny, a Czech visual artist painted the tank pink with friends in April 1991. The Soviet troops left by the end of June that year.

The tank was taken to Prague from a military museum Monday to be placed on a pontoon on the Vltava river to kick off commemorative events, marking the troops' withdrawal.